CVE-2025-11903 is a SQL injection vulnerability identified in the ChanCMS content management system, versions 3.3.0 through 3.3.2. The vulnerability resides in the update function located at /cms/article/update, where the 'cid' parameter is improperly sanitized, allowing an attacker to inject malicious SQL code. This injection flaw enables remote attackers to manipulate backend database queries without requiring authentication or user interaction. The vulnerability's CVSS 4.0 base score is 5.3, reflecting medium severity, with attack vector as network (AV:N), low attack complexity (AC:L), no privileges required (PR:L), and no user interaction (UI:N). The impact includes partial compromise of confidentiality, integrity, and availability of the database, as the attacker can potentially read, modify, or delete data. The vendor was notified but has not issued a patch or response, and while an exploit has been published, there are no confirmed reports of active exploitation in the wild. The lack of vendor response and patch availability increases the risk for organizations relying on ChanCMS for content management, especially those with public-facing installations. The vulnerability's exploitation could lead to unauthorized data access, data corruption, or denial of service, impacting the reliability and trustworthiness of affected websites.

For European organizations, this vulnerability could lead to unauthorized access to sensitive data stored in ChanCMS databases, including user information, content, and potentially administrative data. The integrity of published content could be compromised, leading to misinformation or defacement of websites. Availability could also be affected if attackers execute destructive SQL commands, causing service outages. Organizations in sectors such as government, media, education, and e-commerce that rely on ChanCMS for web content management are at particular risk. Data breaches resulting from exploitation could lead to regulatory penalties under GDPR, reputational damage, and operational disruptions. The medium severity indicates a moderate but tangible risk, especially given the lack of vendor patches and the availability of exploits. European entities with public-facing ChanCMS installations should consider the threat significant enough to warrant immediate mitigation efforts.

Since no official patches are available, European organizations should implement compensating controls immediately. These include: 1) Applying Web Application Firewall (WAF) rules to detect and block SQL injection attempts targeting the 'cid' parameter in /cms/article/update; 2) Restricting access to the update endpoint via network segmentation or IP whitelisting where feasible; 3) Conducting thorough input validation and sanitization on the 'cid' parameter at the application or proxy level; 4) Monitoring logs for suspicious SQL query patterns or unusual activity related to ChanCMS; 5) Considering temporary disabling or restricting the vulnerable update functionality if business operations allow; 6) Planning for an upgrade or migration to a patched or alternative CMS solution once available; 7) Educating development and security teams about the vulnerability and ensuring incident response readiness. Organizations should also maintain regular backups to enable recovery in case of data corruption or loss.